Pvc pipe for water on isuzu dmax

Submitted: Wednesday, Apr 17, 2019 at 15:14

ThreadID: 138176
Views:1599
Replies:8
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Liz C3

We are heading off around Oz in may and wanted to put a 2m long pvc pipe 150mm diameter on top of the dmax truck rack and fill with water, to use for showers. It was weigh abou5 35kgs full. Any ideas whether this is a good idea or bad idea or if insurance will not cover us. Any Feedback welcome.

Just think about the 35kgs of water sloshing around as you stop start. You would need to put baffels in to stop the water going back and forth as you stop start. I have seen ends blow of from the water movement. Mind you that was in the Simpson over sandhills and was the only water they had.

Hi Liz C3, have seen plenty of vehicles with this exact set up you are planning. Make sure when you glue the ends onto the pipe, you clean the pipe & fitting well before apply the glue. I would certainly recommend you also use the red solvent cleaner on the joins prior to glueing as well. I would also suggest you use the “T” joins with screw caps & “O” rings for ends for easy filling. These end caps are also thicker than the pipe itself, and can be drilled so that a tap can be inserted for connecting a hose.

just a thought, as I do not know whether you are on a tight budget or not, I have installed a foot well crossover poly water tank behind the front seats. This tank is both gravity feed or 12v pump, and holds approx. 50lts of water. I have not done the calculations of how much water your system will hold, but the movement of water partially or fully would be a concern at that height. I prefer to have my heavy weights down low ( center point of gravity ). This is only a suggestion.

location - Warragul -Victoria
life is too short, so out and about enjoy

Further to that, the use of two or four 90 degree bends and same length or a bit more to form a closed loop tank of pipe will see the slosh factor halved and a more compact storage possible. Then it can be placed in a more convenient position and still have a cap for filling etc, and may fit in a roof basket if required.

just done a quick calculation volume of a cyclinder using your dimension of 150mm diameter and 2.000mts long multiple that by 2 as well as the same diameter x 1200mm the width approx. by 2 is a volume of 103.020litres. that's 100kg of water dancing around your roof rack, plus the weight of pipe and fittings. All my storm water pipes at home on the shed are 150mm dia due to the surface area. This will still not be a cheap exercise in the purchase of pipe and fittings etc. Should you go down this path, I would put circular baffles in the pipe to slow down the movement of water from side to side and back and forth. Just think of a cattle truck with cattle dancing around on the decks.,a bloody nightmare, or horses in a horse trailer. That is what you can expect. This is why all your tankers have separate cells, and baffles within those cells to slow down this movement.

location - Warragul -Victoria
life is too short, so out and about enjoy

With the water carried on the inside of the 150mm pipe, the diameter being 144mm with a 3mm wall thickness means a total of 2m length is around/close to, 32 litres of water. If straight or in a side by side loop, it is very much the same volume.
So using the outside measurement/dia is probably not the ideal way of calculating.
(7.2cm x7.2) x 3.142 = 162.88 x 200cm = 32.6 L capacity, rounding applied.

that's for the correction RMD. As someone suggested doing a full loop as I understood around the rook rack, using approx. 1200mm for side length, My assumption was an approximate figure based on a rough length not specified length. Still a lot of water high up. Pending on his travel route an numbers in vechile, 10ltr containers for the supermarket may be a good option. Your calculation is for only one length of pipe as I see it. Multiple that by 2 for side by side pipes gives you 65litre splus the 180bends and "T". if I am correct. Please correct me as I was only doing a rough calculation

location - Warragul -Victoria
life is too short, so out and about enjoy

G’day Garry
Yes I can see your info was for a big 4 sided tank. I agree it is far too much weight to go to that total length. In an accident it would promptly leave the vehicle. Shocks would need to be in excellent order to control the mass wandering around up there, OE shock would struggle and it would be like driving a wet sponge.

PVC pipe is not the best for storing drinking water - Poly Vinyl Chloride does leach into the water. use it for washing and showering and use something else for drinking. I have a 90mm PVC rectangular tank circumnavigating my roofrack on a GQ - gives me around 35 litres but would only drink it if desperate. (I used to be in the plastics industry)

Kerry W (WA)
Security is mostly a superstition. It doesnt exist in nature. Life is either a daring adventure or nothing.
-Helen Keller

Macca I think it is a bit different when used as stormwater pipe collecting rainwater as the water is not stored in the pipe,it only travels through it briefly.
A bit like the taste of drinking water from a garden hose left lying in the sun compared to after you flush it through for a minute before drinking it .

AlbyNSW, not necessarily, it depends on how it is set up. Not all down pipes run directly off the roof to the tank, some run along or under the ground for some distance before emptying into the tank. The water contained in these long runs may sit there for several days or even weeks between rainfall events.

Macca,Alby, Yep, it is ok but we can't change the fact that PolyVinylChlorides do leach into the water they are linked to a few forms of cancer, but you have to remember that very few people who install water tanks have your long term health on their list of priorities when designing and installing the plumbing. $$$$? Even though the risk is probably small, like a lot of things we encounter in life eg dust, fumes, other carcinogens etc they take a long time to affect your health or kill you ...but eventually they may - even if they only shave a few years off your potential lifespan but then you'd never know what the real cause of your demise was - if any of the above... Just saying... ;-)

Kerry W (WA)
Security is mostly a superstition. It doesnt exist in nature. Life is either a daring adventure or nothing.
-Helen Keller

You should also investigate the weight load capability of the vehicles roof (roof not rack).
A lot of vehicles cannot carry much weight up there so there might be an insurance risk. 35Kg water + fittings + rack = ??? then add an allowance for gravity & bounce.

Prado 90 is good for around 75Kgs
Prado 120 is around 100Kgs
LC 100 & 200 are around 200Kg

I put a similar sized pvc pipe on the front of a van for a shower I had yrs ago painted black it got quite warm which means the water wants to expand. I tapped in a brass fitting fitted a piece of diff breather hose approx 50mm long and fitted a 60ser cruiser diff breather to that it would trickle 1 - 2lts of water when full which saved the pipe rupturing. I also made a metal baffle to reduce sloshing. Took it off when we sold the van been sitting in the shed for 10yrs.

Not sure about harmful effects from drinking but there are thousands of homes with 1" pvc pipes supply water to their homes from mains supply mine is one built in the 70's neighbours as well built in the 80's. It shouldn't be used for hot water so check safe recommended temp level.